doubt that we are entitled to regard this as the doctrine of Anaximander and Anaximenes.[1] It would arise very naturally in the minds of thinkers who started with water as the primary substance and ended with "air," and it would account admirably for the position of earth and water in the centre and fire at the circumference, with "air" between them. Heavy things tend to the centre of a vortex and light things are forced out to the periphery. It is to be observed that there is no question of a sphere in revolution at this date; what we have to picture is rotary motion in a plane or planes more or less inclined to the earth's surface.[2] It is in favour of the conjecture given above as to the nature of the primordial motion that it provides a satisfactory dynamical explanation of the formation of the δίνη, and we shall find once more (§180) that the Atomists held precisely this view of its origin.
19.Origin of the heavenly bodies. The doxographers also give us some indications of the process by which the different parts of the world arose from the Boundless. The following statement comes ultimately from Theophrastos:
He says that something capable of begetting hot and cold out of the eternal was separated off at the origin of this world. From this arose a sphere of flame which fitted close round the air surrounding the earth as the bark round a tree. When this had been torn off and shut up in certain rings, the sun,
- ↑ I gratefully accept the view propounded by Prof. W. A. Heidel ("The δίνη in Anaximenes and Anaximander," Class. Phil. i. 279), so far as the cosmical motion goes, though I cannot identify that with the "eternal motion." I had already done what I could to show that the "spheres" of Eudoxos and Aristotle must not be imported into Pythagoreanism, and it strengthens the position considerably if we ascribe a rotary motion in a plane to Anaximander's world.
- ↑ This is the plain meaning of Aet. ii. 2, 4, οἱ δὲ τροχοῦ δίκην περιδινεῖσθαι τὸν κόσμον, which is referred to Anaximander by Diels (Dox. p. 46). Zeller's objections to the ascription of the δίνη to Anaximander are mainly based on an inadmissible rendering of the word τροπαί (p. 63 n. 2). Of course, the rotations are not all in the same plane; the ecliptic, for instance, is inclined to the equator, and the Milky Way to both.
